Aiming at the problem of large scale terrain rendering in 3D visualization system of transmission line, a virtual terrain rendering algorithm based on static LOD is proposed. Firstly, the model of terrain elevation data in transmission line corridor is established. The viewing angle is moved into the evaluation factor at the detail level. And the evaluation function is improved by combining the view distance and terrain complexity. On this basis, the variance of the elevation values of the data points in the grid is determined by the threshold value. Different linear interpolation functions are used to simulate the terrain surface. The experimental results show that the proposed algorithm can effectively reduce the number of terrain triangles in motion. The virtual scene frame is more smooth and has a good effect of terrain simulation.